Maybe Chris O’Donnell didn’t seem like the obvious choice to play this guy, but his casting could turn out to be brilliant: There’s a stoic, blank-slate quality about the actor that allows you to believe he could fly under the radar (or have room to take on an entirely new persona). And yet, there’s a softness in his voice that makes you want to get close to him, to protect him like his partner, LL Cool J’s Special Agent Sam Hanna (who told G that he’ll give him his first birthday card ever this year, then joked that he’ll put a personality in it — ha!), or cover him up with a blanket like Hetty (Linda Hunt, on a step stool), who is apparently in charge of the office’s gadgets, wardrobe, and expense reports.

Something else I like about Callen and Sam: Their willingness to kick a little ass. Don’t get me wrong: I’m a fan of Gibbs’ killer sniper skills and Tony’s penchant for suits on NCIS. But it’s nice to know that Ziva isn’t the only one who likes to get down and dirty in that organization.

What’s your take on Chris O’Donnell as Callen? Will you be tuning in next week?